Various types of sprinklers have been employed heretofore in commercial and residential environments which employ a pattern producing nozzle assembly. Exemplary thereof is my prior U.S. Pat. No. 3,854,664 which discloses a multiple orifice nozzle of cylindrical configuration rotated about a center shaft by water turbine means and a pattern plate positioned beneath the nozzle to control the pattern of water emitted from the nozzle. The pattern plate is fixed in the sprinkler and has its pattern producing orifice off set from a center line of the nozzle since the nozzle is driven via a center shaft arrangement. In addition to this commercial type sprinkler, there are residential use type pattern sprinklers which operate off garden hoses which have a turret which rotate over a fixed head, the head having individual stationary pattern plates selected by movement by the turrent relative thereto. Such pattern sprinklers are not adjustable to different size patterns, but are designed to give a certain shape of pattern whose size may vary to the water pressure provided by the water conduits to which they are attached.
It would therefore be desirable to provide a pattern type sprinkler wherein different patterns can be easily selected and yet the size of the pattern area sprinkled can be selectively varied and the water distribution over the pattern be maintained in a uniform manner.